Engine Build for Barracuda - Project B3 Gets A Block-In-A-Bag

1/30The engine for our bracket 'Cuda has come a long way thanks to a block-in-a-bag from Chenoweth Racing Enterprises and a bunch of new and used go-fast goodies from various sources.

Since we're building the engine for our bracket-racer project it must mean the car is ready to go, right? Well, not quite. While we have made some progress on our '67 Barracuda's floors, chassis, and suspension, we still have a long way to go before it's ready for the track. We still need to finish our rollcage, swap our windows for polycarbonate (Lexan) replacements, install a stout rearend, build a transmission, as well as plumb and wire the car.

There are several reasons, however, why we will be building the engine at this stage of the project. First, we will need the engine and transmission in place to complete our plumbing and wiring, as well as to fit our headers and motor plate. Second, we were tired of the parts taking up shelf space so we decided to bolt the engine together. Third, and most important, having the engine ready to install will motivate us to get off our butts and complete the car!

Those of you who have been following our project will remember that our objective for this car is mid-10-second elapsed times. Since our Barracuda will weigh in at just about 3,000 pounds, we'll need an engine that produces in the neighborhood of 600 hp to achieve our goal. Knowing that it's easier to slow a car down than speed it up, and wanting to be able to run mid-10s even in hot weather, we'll shoot for a power more in the 650hp range for this build. We also want to ensure this engine has the endurance to last multiple seasons of racing, so we'll need some strong parts, especially in the bottom end.

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The budget for our entire car is about $10,000, so we'll utilize some used items and some good factory parts as well. Since the engine of a drag car is its most abused component, we'll be spending a significant portion of our budget on this motor.

When deciding what engine to drop in our 'Cuda, we first had to consider what we had available. Our goal of 10-second elapsed times pretty much dictated big-block power, and we just happened to have a 400 big-block available that didn't cost us a dime. Since making 650 hp from 400 cubes would be tough, we decided to match our 400 block with a forged 440 crank that we also had at the shop to net a displacement of 451 ci. We've found the low-deck 451 engine to be a powerful and durable combination, also making plenty of torque to get our 'Cuda moving. This combination does require that the crank's main journals be turned down to the main journal size of the 400 and some clearancing of the block in the main-webbing area, but other than that, it's a straightforward build since several manufacturers offer pistons for this application. our block would need to be machined, and for that we sent it to Chenoweth Racing Enterprises.

3/30Prior to shipping our block to Chenoweth Racing, we disassembled it and gave it a quick degreasing. Mopar 400 blocks are readily available, heck, a brand-X racer at our local track gave us this one just to make room in his shop!

You may remember the guys at Chenoweth since we have featured their main girdle in several of our engine builds. What you may not know, however, is that the Chenoweth shop offers full-service machining and is extremely Mopar friendly. We chose to send our block to them for their "block-in-a-bag" service, which includes fully machining the block for a racing application on their state-of-the-art equipment. This service is a great option for those who don't have a trustworthy machine shop in their area or for those who want to know they're getting the best quality machine work for their money. The block-in-a-bag service includes fully blueprinting the engine block, decking and squaring all surfaces, boring and honing the cylinders with torque plates, and line-boring the main journals. All the work is done on new Rottler equipment, which can hold tolerances much more accurately than the antiquated equipment found in some shops.

As our block was being machined, we formulated a plan for the rest of our build. While our factory forged crank would certainly handle this engine's power, we weren't so sure about the factory rods, so Eagle 6.76 length H-beams were ordered. Ross-forged domed pistons were matched to the Eagle rods, and the rotating assembly was sent to Auto Performance Engines to be balanced. When it came to cylinder heads we had a dilemma: should we spend the money to machine a set of steel heads or purchase aftermarket units? Fortunately, while at a local swap meet, the decision was made for us. We scored a used pair of Edelbrock Performer RPM heads for a grand that were complete and already had some bowl work done. At the same swap meet, we also scored a sweet deal on a set of K-motion valvesprings that would allow us to run a pretty stout roller cam, so we completed our transaction and had the top end for our engine. While there is always a risk when purchasing used parts, we minimized this risk by having our parts thoroughly checked before we installed them.

We decided to use new, high-quality parts for the remainder of our engine. For our oil system, we chose a Milodon kit featuring an eight-quart, low-profile oil pan and a single external pickup. This oil system is great for drag racing and is good for rpm in excess of 7,000. When it came to camshaft selection, we went with a custom-ground Comp solid roller unit that we've successfully used in the past. This camshaft features .660-inch lift for both the intake and exhaust valves, with duration at .050-inch lift numbers coming in at 284 and 288 degrees, respectively. With a lobe separation of 108 degrees, we've found this cam to provide broad torque and power curves, which is the key to making a bracket racing engine consistent. We also chose Comp's 1.5 ratio roller rocker arms and their roller timing set to complete our top end. For induction, we topped our engine with a Mopar Performance M-1 intake manifold matched with a Holley 1050-cfm Dominator carburetor. Exhaust duties will be handled by Hooker's fenderwell exit headers with 2-inch primaries and 3.5-inch collectors. To light the fires, we chose an MSD Pro-billet distributor. Federal-Mogul bearings were utilized throughout our engine, and Speed-Pro rings combined with Cometic multilayer steel head gaskets helped to seal the cylinders.

Assembling this engine was easy thanks to the accurate machine work performed by Chenoweth Racing. We checked all our block's dimensions prior to assembly and found them to be well within the prescribed tolerances. While we won't be putting this engine on the dyno, we will be testing it at the track once the rest of the project is complete. In our experience this combination should be good for realistic horsepower numbers in the 650 range and should have no problem propelling our '67 'Cuda well into the 10s in the quarter-mile.

Be sure to stay tuned to future issues as we complete the car and head to the track for some testing.